The field of this invention relates to an apparatus for constructing large or small three dimensional objects from a fluid medium with the building of the three dimensional object being accomplished through the use of a continuous extrusion of a viscous, ultraviolet light, fast cured fluid medium from a dispensing nozzle in association with an ultraviolet light and object support platform with relative movement between the nozzle and the support platform being directed by an operator or preprogrammed computer.
Previously, a computer aided design system has long been known. By utilizing a computer, an operator is able to design three dimensional objects and display that design on a monitor. The monitor is used to visually represent the design that is wanted by the operator. The design can be changed within the computer aided design system altering its shape and/or increasing or decreasing its size with the changed shape displayed on the monitor. Once the desired shape and size has been obtained, as an artist's mental image or on a computer screen, the artist/operator can produce the first layer of the object by extrusion of a continuous bead of a viscous liquid in the outline of the object and, then by raising the dispensing nozzle height by the diameter of the bead and repeating the outline-producing movement, the machine forms the object layer by layer.
Within the prior art, U.S. Pat. No. 4,665,492, inventor William E. Masters, produced prototypes in a similar manner wherein individual particles of material are propelled from a nozzle to a particular location and the prototype is built in this manner.
The system of U.S. Pat. No. 4,665,492 has the potential of being accurate when using small particles but is a slow and time consuming procedure when creating a large object like a boat hull or car exterior. The alternative of using large particles would expedite the process but would create a very rough overall effect in contrast to the smooth bead created by the proposed continuous extrusion fabrication process of this invention. Large smooth contoured shapes cannot accurately and quickly be obtained with the system of U.S. Pat. No. 4,665,492.
Also, within U.S. Pat. No. 4,575,330, invented by Charles W. Hull, a three dimensional object is created by solidifying a narrow bead within a bath of resin with a laser beam one layer at a time. This system of U.S. Pat. No. 4,575,330 produces a partially cured accurate shape contained within the resin bath which is then post cured after removal from the bath.
Several disadvantages of the Hull patent are apparent. For large parts, such as automobile exteriors, the Hull patent would require a resin bath larger than the object to be made. Enough resin to fill a twenty foot long bath for an automobile exterior, is prohibitively expensive. Also, to solidify a bead large enough to be structurally stable when making a twenty foot long part requires a very powerful laser involving great expense as well as presenting a dangerous work environment. In addition, the Hull patent requires post curing. The Hull patent has a lack of structural rigidity for large objects prior to post curing. Handling of large objects for post curing would be most difficult. Large objects cannot be quickly and economically formed by using U.S. Pat. No. 4,575,330.
However, the aforementioned patents, as well as the present invention, are for the purpose of satisfying a long existing need in the design and production field for rapidly and reliably creating an object from design concept to a tangible form. Typical structures could range in size from small objects such as special shaped bottles to very large designs such as statuary, aircraft aerodynamic shapes and ship hull hydrodynamic test shapes.
Individuals who have been concerned with the development of production of three dimensional objects both small and large, have long recognized the desirability for improvement in a more rapid, reliable, economical means which would facilitate moving from a design stage of an object to a finished product. It is the intention of the present invention to answer that need especially for economically producing very large objects which has not been possible using prior art.
Another field of usage of the apparatus of the present invention is to use the apparatus to produce complex movie set pieces which are large and of imaginative irregular shapes which when shown on film appear to be most realistic. Cost as well as time required utilizing the subject continuous extrusion of the present invention to produce movie sets is substantially decreased from traditional fabrication methods.